ABSTRACT
Introduction: Patients with MS (pwMS) are currently receiving different COVID-19 vaccines in several Latin American countries. However, questions arise around the safety of these vaccines and whether vaccination might increase the risk of relapse activity. Therefore, we aimed to assess the safety and occurrence of relapses following COVID-19 vaccination in Latin American pwMS. Methods: A web-based survey was completed by 207 pwMS from Latin America to assess for adverse events associated with COVID-19 vaccination between February 1 and April 30, 2021. Results: All participants received the first dose and 84 the second. The different vaccines administered were: inactivated virus vaccines [(IVV);CoronaVac, BBIBP-CorV) ] in 117 (56.5%) patients, adenovirus vector vaccines [(AdV);Gam-COVID-Vac, AZD1222] in 53 (25.6%) and mRNA vaccines (BNT162b2) in 37 (17.9%). The mean follow-up after vaccination was 24 ± 16 days. Three (1.4%) patients reported having COVID-19 infection after vaccination (all occurring after the first dose). Any adverse events were reported in 61 (29.5%) and 23 (27.4%) individuals after the first and second doses respectively. These included pain at the injection site, headache, fever, flu-like symptoms, fatigue, and muscle or joint pain. A lower frequency of adverse events was found with IVV (x?=7.2, p=0.03). Four (1.9%) patients reported an MS relapse, all occurring after an IVV first dose. Mean time to relapse: 18 ± 13 days. None of these patients had stopped or postponed their MS treatment before vaccination. Conclusion: COVID-19 vaccines seem to be safe for pwMS from Latin America. No major safety signals appeared in this patientreported study.